How about adding the EZSMART Square & Handle Combo ( does that attach to the track saw system ???)

I've got a limited budget, any advice appreciated.

When you throw in the term "Best" there is always room for debate. I use to build cabinets professionally and found that I used the square and UEG a lot. The EZ One also came in good for a lot of the speciality cuts. The EZ system is a great system for shelves and bookcases. Eyeryone is going to tune the system to meet their needs. Don't forget the the Smart router kit. I've never found a better way to make dado's.

What Burt said. But if you're cutting more than one piece the same length also get the Cabinetmaker. I think it's the best tool EZ's made, though they could make it less clunky. Amazing how nice it is to be able to do repeat cuts all the same width.
Also all your long cuts are with the UEG, you'll only crosscut with a track, and likely narrower than 48". So you don't need 108" of track. Just get a 55".

Looked at the EZ site, boy is it hard to navigate, looks like the Cabinetmaker includes the Square but best to ask EZ.
If you decide to just buy the Square, I'd save myself the money and just buy a couple of short connectors and make a square using scrap ply. Save you $100.

The Cabinetmaker is the EZ Miter Square plus ONE EZ Repeater ... plus the handle if you buy/use it. It allows you to make quick repeatable miter cuts.

Back to the track (also called a guide rail). In days of old EZ was using the Repeaters (two Repeaters attached to a length of guide rail) to quickly break down plywood into repeatable widths. You pick you length of guide rail as needed.

Today the Repeaters seem to have been replaced with the Universal Edge Guide (UEG), which is simpler, faster, just as effective, ... BUT only if the factory edge is relatively straight. The UEG can "average out" some minor waviness of the factory edge. If it is not straight, then you will need to create a new straight edge using a guide rail. Of course using only the UEG is a VERY cost effective way to start.

What lengths of guide rail do you want? My first two tracks were 50" long. That gave me only a 2" "starting pad" (where you set the saw before starting cutting - you don't need much room on the end of the cut - but I think you need some - maybe 4") when cutting 48" plywood, and only a 4" "starting pad" when cutting 96" plywood. Neither was very good for me. So I recently added a 64" length. I think using a 64" guide rail (for 48" cuts) and adding a 48" guide rail (for 96" cuts) is my preferred, giving 16" for start+stop pads for both 48" & 96' cuts). You have to buy a custom length of 48", along with the anti-chip edges to match (or get 52" length and cut them down with a utility knife).

I think the 108" package is two 54" lengths, and the 144" package is two 72" lengths. I suspect that the 118" package is one 54" length and one 64" length.

I also think that the 48" track would be a nice size to use with a Cabinetmaker. Long enough to work with most needs and short enough to handle. In use some of the track is behind the miter square as a launch pad and most is in front doing the cutting work.

In the past I've broken down plywood with just the tracks. I bought the Repeaters - only used them once so far. The jury is not yet in on how I like them. A bit awkward due the side and weight when cutting 96". I only bought the UEG last week to see how it will work.

Once you've ripped the lengths needed, then you'll need to cut them down to size. The low cost way to do that is to use the miter square with a shortish length of guide rail. Keep in mind the need for a launchpad in front of the square. I have an older model that only cuts 90 degree cuts and LOVE it. The miter square gives you more options. Of course the EZ-1 gives you tons of options.

With my miter square I found the handle got in the way. I stopped using it. Its kind of expensive and not required, so if you can I'd suggest trying without and seeing how it goes for you.

I personally have not yet used my repeater with the square (a cabinetmaker), but it makes so much sense as a very fast and accurate way of making repeated cross cuts. Personally I just measured very carefully and used the tracks, though I think using a stick of desired length would work better than repeated measurements. Still, in the end I set my sights on getting an EZ-1. I recently bought a used one (yipeee) for Christmas (my excuse). Its not even (re)assembled yet, but it will be great.

Regarding the saw to buy. If you are buying an EZ Ready saw - what I did - consider the depth of cut. I wish Eurekazone would report the actual depth of cut with the base on - both on (subtract 0.9 inches) and off (subtract 0.4 inches) the guide rail. My Hitachi on the old base just barely does NOT cut through a 1.5 2x4 cut. I have to finish it with my pocketknife. If my calculations are right, the Makita 5007 and the Dewalt will cut a bit deeper than 1.5" (1.6-ish) and the Hitachi and the Rigid will cut just less than 1.5" (1.4-ish).

My list would for what you want to do:

Makita 5007 or Dewalt EZ Ready Saw (check depth)
Base
Universal Edge Guide
Miter Square (no handle)
48" guide rail with anti-chip edges for cutting down the lengths. I worry the 64" is too big to handle with the miter square.
One Repeater (to make the Cabinetmaker) ... or use a stick to measure, or just measure VERY carefully and use the rail (with clamps) to cut down.
Super Smart Router Kit is the way to go for dadoes and rabbets, ... I use a Bosch 1617 router and bought an extra plunge base to keep on the SSRK.

If the factory edges are OK, then later you can buy a 64" guide rail with anti-chip edges and 2 connectors, if not, buy them now. Or you could buy the 64" first.

Oh, and I have the Smart Table - now the Multiform table - put on banquet table legs. Its awesome!!! But it is also expensive. You can just put a sheet of plywood on some sawhorses and add a sheet of foam board as a sacrificial surface. If clamping with a guide rail you'll need a smaller surface to give clamp room for the 48" cuts.

This is all just my two cents worth. I don't consider myself an expert.

I also build cabinets from 4' x 8' sheets of plywood and use the UEG and Cabinet Maker - the UEG to rip the sheet to width and the Cabinet Maker to cut to finished length. I tried the repeater once and didn't like it - too clunky and fussy for my taste. I made a sliding stop for the Cabinet Maker - teamed with a longer square from EZ, it's perfect for cutting identical parts to length. Mark the length on the first part, set the ACE on the mark and move the sliding stop to touch the end of the strip. You can keep cutting identical length parts all day long, but it's easily changed to cut different lengths. For me, it has worked out way better than the repeater. I sized the length to be able to cut base cabinet sides (34-1/2") plus a little extra.